I Greece,I had 2000 men and won against 2400 macedonian elites and that would be a heroic for me. In arabia i had 3000 against 3600 and that was heroic cause i lost like 100 men
see, In arabia heroic victories are easier earned than in Greece, provided offcource you attack them in a sensible manner(so not with ... Chatti youth, and ... Pantodapoi spearmen).

although sabeans arent that bad.
They are not exactly bad, they are just squishy and easily countered. Especially as the terrain (while not adequately impeding non desert troops) is wide and open and thus is perfect for any strategies involving cavalry, archers and most of all cavalry archers. One could say their troops are similar to sweboz troops - few armor, but great other stats, they also get a terrain bonus, however Sweboz have the added comfort of trees in their area, which unlike desert HAS significant ingame effects on cavalry and ranged units.
I normally get a suitable general(if KH I take a mercenary eastern or Steppe one) give him some (mercenary) horse archers, a unit of heavy cavalry and let him swoosh through arabia without much losses.